A 60-year-old man comes to the office due to 2 months of low back pain unresponsive to over-the-counter analgesics.  The pain is worse at night and interferes with sleep.  On examination, the lumbar vertebrae are tender to palpation, and the prostate is indurated and firm.  After a thorough evaluation, leuprolide therapy is started.  Which of the following changes in testosterone (solid line) and dihydrotestosterone (dashed line) levels are most likely to occur in this patient after initiation of therapy?

A 64-year-old man comes to the office due to urinary frequency, hesitancy, and dribbling.  His symptoms began insidiously 5 years ago and have progressively worsened.  He has to get up 2 or 3 times each night to urinate.  Vital signs are normal.  Examination shows a smooth, symmetrically enlarged prostate without nodules or tenderness.  There is no suprapubic tenderness.  Prostate-specific antigen level is 3.5 ng/mL, creatinine is 1.2 mg/dL, and urinalysis is normal.  The patient is started on a new medication.  After 6 months of therapy, his urinary symptoms improve and prostate volume decreases by 20%.  Which of the following medications is most likely responsible for the decreased prostate volume in this patient?

A 65-year-old man with benign prostatic hyperplasia comes to the office for a follow-up appointment.  He has a history of obstructive urinary symptoms that were unrelieved with tamsulosin, and a new medication was prescribed at his last visit 8 months ago.  Since starting the new medication, the patient has experienced gradual improvement in urinary hesitancy and strength of urinary stream.  However, he also has noticed a significant increase in the size of his breasts.  The patient reports no pain or changes in weight.  Glandular tissue, approximately 2 cm in diameter, is palpated under the nipples and is mildly tender to palpation.  There is no nipple discharge, breast asymmetry, or rash.  This patient’s breast findings are most likely due to which of the following drug effects?

A 46-year-old woman comes to the clinic to establish primary care as a new patient.  She is a marathon runner but has been unable to train due to a vertebral stress fracture diagnosed via x-ray during a recent emergency department visit.  She has a history of hypothyroidism for which she takes levothyroxine.  The patient’s last menstrual period was a year ago.  Her diet consists mainly of vegetables and fruit, and she takes a daily multivitamin.  Her mother died of breast cancer at age 52.  The patient is concerned that her family history puts her at risk for breast cancer.  X-ray absorptiometry studies demonstrate abnormally low bone density in the lumbar vertebrae.  Which of the following drugs is the most appropriate option for decreasing the risk of both bone fractures and breast cancer in this patient?

A 22-year-old man comes to the office due to erectile dysfunction and lack of sexual desire.  Medical history is unremarkable.  The patient is in a stable relationship with his fiancé and does not use tobacco, alcohol, or illicit drugs.  Height is 188 cm (6 ft 2 in) and weight is 88 kg (194 lb).  Examination shows bilateral gynecomastia, sparse facial hair, and small, firm testes.  The penis is normal in size and peripheral vision is normal on confrontation.  This patient would most benefit from which of the following?

A 68-year-old man comes to the office for follow-up.  The patient underwent radical prostatectomy for prostate adenocarcinoma 6 months ago, which decreased his serum prostate-specific antigen (PSA) level from 16 ng/mL at the time of surgery to 1 ng/mL 6 weeks after surgery.  Initial staging evaluation revealed no evidence of metastatic disease.  PSA level is now 8 ng/dL, and repeat imaging reveals regional lymphadenopathy.  The patient is prescribed combination therapy with buserelin and bicalutamide.  Which of the following is the main reason for adding bicalutamide to this patient’s treatment regimen?

A group of premenopausal women participate in a clinical trial for a medication used to treat endometriosis.  Prior to initiation of the medication, all the women had normal premenopausal levels of gonadotropin-releasing hormone (GnRH), FSH, and estrogen.  The medication is administered continuously, and the patients’ hormone levels are recorded over the next two months, with the results shown below:

This effect is most likely caused by which of the following medications?

A 65-year-old woman comes to the emergency department due to left leg pain and swelling for the past day.  She has had no trauma or fever.  The patient has a history of hypertension, congestive heart failure, type 2 diabetes mellitus, and osteoporosis.  Family history is notable for breast cancer in her mother and sister.  She takes multiple medications.  Temperature is 37.8 C (100 F), blood pressure is 130/80 mm Hg, and pulse is 99/min.  Pulse oximetry shows 98% on ambient air.  The lungs are clear to auscultation, and heart sounds are normal without murmur.  There is tenderness and edema of the left lower extremity up to the mid thigh.  Venous Doppler ultrasonography reveals an occluding thrombus in the left femoral and popliteal veins.  Which of the following pharmacotherapies most likely contributed to this patient’s current condition?

A 52-year-old man is in the hospital burn unit 3 days after sustaining severe burns to 35% of his body surface area in a house fire.  The patient remains intubated due to inhalational injury and has been undergoing staged excision and grafting of his burns.  There has been no clinical evidence of infection, but the patient has been persistently febrile, hypertensive, tachycardiac, and hyperglycemic.  Treatment with oxandrolone, a synthetic testosterone analogue, is considered.  The beneficial effect of this treatment is most likely related to its effect on which of the following processes?

A 30-year-old nulligravid woman and her 31-year-old husband come to the office for an infertility evaluation.  They have been unable to conceive despite 2 years of unprotected intercourse.  The patient has had irregular periods since menarche, ranging between 30 and 70 days each cycle.  Her BMI is 34 kg/m².  Examination shows a small, anteverted uterus and bilateral enlarged ovaries.  A urine pregnancy test is negative.  The patient is prescribed letrozole for ovulation induction therapy.  Which of the following is the mechanism of action of this medication?

A 24-year-old man comes to the emergency department due to a persistent, painful erection that has lasted for more than 8 hours.  He had 3 similar episodes in the past 2 years that were less than 30 minutes in duration and resolved with ice packs at home.  The patient has had no trauma to the perineal or genital area.  He has no other medical conditions and takes no prescription, over-the-counter, or herbal medications.  The patient does not use tobacco, alcohol, or illicit drugs.  Temperature is 37 C (98.6 F), blood pressure is 124/82 mm Hg, pulse is 84/min, and respirations are 16/min.  Examination shows an engorged corpora cavernosa and a rigid, tender penis.  The testicles are normal, and the remainder of the examination shows no abnormalities.  Penile injection with a medication having which of the following mechanisms would most likely relieve this patient’s symptoms?

A 65-year-old man with benign prostatic hyperplasia has moderately severe symptoms and is started on finasteride.  After six months of treatment with finasteride, his symptoms improve markedly and his prostate has regressed in size.  Which of the following histological patterns was most likely present at the time of initiation of treatment?

A 40-year-old man comes to the office due to erectile dysfunction and loss of libido.  The patient’s history is notable for Hodgkin lymphoma that was treated with chemotherapy.  Physical examination is normal except for small testes.  Laboratory evaluation shows consistently low total and free early morning testosterone levels and elevated serum LH.  Transdermal testosterone therapy is prescribed.  Which of the following should be periodically monitored during this patient’s treatment?

A 75-year-old man comes to the office due to 4 weeks of increased urinary hesitancy and progressive low back pain.  Spinal imaging reveals multiple lesions suspicious for metastatic cancer.  Biopsy of a bone lesion shows well-differentiated adenocarcinoma.  Treatment with a medication that does which of the following would most likely reduce the spread of this patient’s cancer?

A 60-year-old man comes to the office for follow-up after a recent emergency department visit due to cough.  The patient was diagnosed with acute bronchitis and the symptoms resolved with symptomatic treatment.  A chest x-ray obtained during that visit revealed no lung abnormalities, but the bones appeared osteopenic.  The patient reports no bone pain and has had no fractures.  He has a history of prostate cancer treated with radiation therapy and is taking leuprolide.  The patient has no other medical problems and has no known drug allergies.  He drinks a glass of wine daily and does not use tobacco or illicit drugs.  He eats a balanced diet and exercises regularly.  Blood pressure is 120/80 mm Hg and pulse is 80/min.  Physical examination shows no abnormalities.  A dual-energy x-ray absorptiometry (DXA) scan shows low bone mineral density.  Which of the following is the most likely underlying mechanism of the observed finding in this patient?

A 58-year-old man comes to the emergency department due to vision disturbances.  Over the past several weeks, the patient has had intermittent episodes in which he sees everything tinted with blue.  His vision returned to normal within a few hours each time.  When he woke up today, vision in the left eye was blurry.  He has had no eye pain, conjunctival redness, or headache.  The patient has tingling and numbness in the feet due to diabetic neuropathy, which is unchanged, and reports no other focal weakness or sensory loss.  Medical history is notable for hypertension, type 2 diabetes mellitus, hyperlipidemia, and erectile dysfunction.  Vital signs are within normal limits.  Physical examination shows an afferent pupillary defect, decreased visual acuity, and optic disc edema in the left eye.  Discontinuing which of the following medications may improve this patient’s vision?